London A.H. Burkitt notes that among the very old symbols still used in London at that time, which were based on associations between pagan gods and professions, "we find Mercury, or his caduceus, appropriate in trade, as indicating expedition. Esculapius, his Serpent and staff, or his cock, for professors of the healing art". Adoption by the US military Widespread confusion regarding the supposed medical significance apparently arose as a result of events in the United States that occurred in the second half of the 19th century. As pointed out by Garrison, the caduceus had appeared on the chevrons of Army hospital stewards as early as 1856 (William K. Emerson indicates the insignia was adopted earlier, in 1851). It has been asserted that this was a result of ignorance or misinterpretation regarding the pre-existing designation of the rod of Asclepius by the Surgeon General of the United States for this purpose. It is worth noting that hospital stewards were not physicians; they played a supporting role preparing drugs for surgeons, supervising nurses and cooks, maintaining accounting and medical records, and in emergencies sometimes performed minor surgery or provided prescriptions. Later, in 1871, the Surgeon General designated the caduceus as the seal of the Marine Hospital Service (destined to become the U.S. Public Health Service in 1912). Gershen states that the change was for aesthetic reasons, whereas Friedlander states the caduceus was adopted by the Marine Hospital Service "because of its relationship with merchant seamen and the maritime industry". The caduceus was formally adopted by the Medical Department of the United States Army in 1902 and was added to the uniforms of Army medical officers. According to Friedlander, this was brought about by one Captain Frederick P. Reynolds, although Bernice Engle states "the use of the caduceus in our army I believe to be due chiefly to the late Colonel Hoff, who has emphasized the suitability of the caduceus as an emblem of neutrality. Reynolds had the idea rejected several times by the Surgeon General, but persuaded the new incumbent — Brig. Gen. William H. Forwood — to adopt it. This resulted in considerable controversy. The Army and Navy Register of 28 June 1902 discusses the argument, which reflects the fact that a number of medical officers were unhappy with the choice. The article editor claims that the symbol was not chosen for its medical connotations and proposes the following symbolic interpretation: